Cap

ABSTRACT

A cap includes: a cap body including a top plate and a skirt having a tubular shape disposed on a circumferential edge of the top plate, a sealing member disposed on an inner surface of the top plate and configured to seal a mouth of a container, a slit extending in a circumferential direction of the skirt, and a worked portion formed at least in a part of the slit in the circumferential direction on at least a side of the slit closer to the top plate.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation Application of PCT Application No. PCT/JP2022/010040, filed Mar. 8, 2022 and based upon and claiming the benefit of priority from Japanese Patent Application No. 2021-036399, filed Mar. 8, 2021, the entire contents of all of which are incorporated herein by reference.

FIELD

The present invention relates to a cap for sealing a can container that stores a drink.

BACKGROUND

In the related art, there is known a cap having a top plate and a skirt for sealing a container mouth. Jpn. Pat. Appln. KOKAI Publication No. 2008-056323 discloses a cap including a skirt provided with a slit in order to release an internal pressure of a container when the container is opened. In such a cap, a corner connecting a top plate and a skirt is formed by drawing when capping a mouth of a container (attaching the cap to the mouth of the container).

PATENT LITERATURE

-   Patent Literature 1: Jpn. Pat. Appln. KOKAI Publication No.     2008-056323

SUMMARY

In a case where such a cap is provided with a slit having a long circumferential length, an upper end of the slit may be deformed at the time of drawing of a corner of a cap body when a container mouth is capped with the cap.

Therefore, an object of the present invention is to provide a cap capable of preventing deformation even with a slit having a long circumferential length.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view showing configurations of a cap and a can container according to an embodiment of the invention.

FIG. 2 is a side view showing the configuration of the cap.

FIG. 3 is a plan view showing the configuration of the cap.

FIG. 4 is a cross-sectional view showing the configuration of the cap.

DETAILED DESCRIPTION

According to an aspect of the invention, a cap includes: a cap body including a top plate and a skirt having a tubular shape disposed on a circumferential edge of the top plate, a sealing member disposed on an inner surface of the top plate and configured to seal a container mouth, a slit extending in a circumferential direction of the skirt, and a worked portion formed at least in a part of the slit in the circumferential direction on at least a side of the slit closer to the top plate.

Hereinafter, a cap 1 according to an embodiment of the invention will be described with reference to FIGS. 1 to 4 .

FIG. 1 is a side view showing configurations of a cap 1 and a can container 100 according to an embodiment of the present invention. FIG. 2 is a side view showing the configuration of the cap 1 before capping a mouth of the can container 100 (container mouth). FIG. 3 is a plan view showing the configuration of the cap 1. FIG. 4 is a cross-sectional view showing the configuration of the cap 1 taken along line IV-IV of FIG. 3 .

As illustrated in FIG. 1 , the cap 1 is mounted on the mouth of the can container 100 and twisted around the mouth tightly to seal the mouth. First, the can container 100 will be described with reference to FIG. 1 .

As illustrated in FIG. 1 , the can container 100 is what is called a bottle type container for storing a drink or the like. For example, the can container 100 includes a metal material such as an aluminum alloy and a surface-treated steel plate in which a resin film is laminated on both surfaces. The can container 100 is formed into a cylindrical shape having different outside diameters, that is, a cylindrical shape with one end reduced in diameter. The can container 100 has one end provided with the mouth for discharging the drink stored therein. The mouth has the outer periphery provided with a jaw, a male thread, and a curled portion in this order from the bottom to the end of the can container 100.

The jaw protrudes annularly. The curled portion is smaller than the male thread in diameter. Furthermore, the curled portion has a diameter smaller than an inside diameter of the cap 1. The curled portion is formed by bending an end of the mouth once or more. The curled portion constitutes an opening for discharging the drink stored in the can container 100.

As illustrated in FIGS. 1 to 4 , the cap 1 includes a cap body 11 and a sealing member 12 disposed inside the cap body 11 in an integrated manner or separately. In this embodiment, the cap 1 will be illustrated as an example having the sealing member 12 disposed inside the cap body 11 in an integrated manner.

The cap body 11 includes a material obtained by forming a resin film layer on a metal material such as an aluminum alloy. The material having a thin plate shape is subjected to processes such as drawing, knurling, roll-on process, and pressing, thereby forming the cap body 11 into a cup shape.

As illustrated in FIGS. 1 to 4 , the cap body 11 includes a disk-shaped top plate 21 and a cylindrical skirt 22 hanging down from a circumferential edge of the top plate 21. In the cap body 11, the top plate 21 and the skirt 22 are formed in an integrated manner, being continuous with each other through a corner 23 having an annular and curved or linear shape.

The top plate 21 has a disk shape. As illustrated in FIGS. 1 and 4 , the top plate 21 has a main surface formed into a planar shape. Note that at least a part of the top plate 21 may be subjected to embossing and debossing.

The skirt 22 has one end continuous with the top plate 21 through the corner 23 and the other end being opened. As illustrated in FIGS. 1, 2, and 4 , the skirt 22 includes a plurality of knurled portions 31, a plurality of slits 32, a worked portion 33 disposed in each slit 32, a female thread 34, and a tamper evident band 35. In the skirt 22, for example, an end portion closer to the top plate 21 is provided with the plurality of knurled portions 31, the plurality of slits 32, and a plurality of worked portions 33, and a central portion is provided with the female thread 34, and an opening end portion is provided with the tamper evident band 35.

A cup-shaped molded product including the top plate 21, the cylindrical skirt 22 (not provided with the plurality of knurled portions 31, the slits 32, the female thread 34, and the tamper evident band 35), and the corner 23 is subjected to processes such as knurling and roll-on process, thereby forming the skirt 22 provided with the plurality of knurled portions 31, the plurality of slits 32, the female thread 34, and the tamper evident band 35. Furthermore, the female thread 34 is formed at the time of capping the can container 100 with the cap 1 mounted on the can container 100.

The knurled portions 31 are recesses formed by denting the skirt 22 radially inward. For example, some of the plurality of knurled portions 31 are arranged at equal intervals in a circumferential direction, and each slit 32 is placed between knurled portion groups where some knurled portions 31 are arranged at equal intervals.

As illustrated in FIGS. 1 to 4 , the slits 32 extend in the circumferential direction of the skirt 22. For example, each slit 32 has a circumferential length longer than a circumferential length of one knurled portion 31. The slits 32 protrude from the inner periphery of the skirt 22. The slits 32 are cutouts used for discharging gas inside the can container 100 when the can container 100 is opened. A preferred circumferential length of the slits 32 is, for example, from 5 mm to 20 mm. There are, for example, more than one slit 32 but the number of slits 32 may be one.

The plurality of knurled portions 31 and the plurality of slits 32 are arranged, for example, in the circumferential direction. For example, in this embodiment, the skirt 22 is provided with twenty-one knurled portions 31 and three slits 32 in the circumferential direction. Seven knurled portions 31 are arranged at equal intervals, and the slits 32 are arranged at 120-degree angular intervals between three knurled portion groups each including seven knurled portions 31. In addition, three slits 32 are arranged in the skirt 22 at equal intervals or substantially equal intervals in the circumferential direction.

The worked portions 33 are disposed in at least a part of each slit 32 in the circumferential direction on at least a side of the slit 32 closer to the top plate 21. In other words, at least one part of the skirt 22 between both ends of each slit 32 on the side of the slit 32 closer to the top plate 21 is provided with the worked portions 33. The worked portions 33 are, for example, recesses or protrusions disposed in the skirt 22.

As a preferred example, two worked portions 33 are disposed in each slit 32 at both ends or both end portions, but more preferably, at the both ends. Furthermore, as the preferred example, the worked portions 33 are disposed only on the side of each slit 32 closer to the top plate 21. Herein, both end portions of each slit 32 represent areas about 1 mm to 2 mm from both ends of the slit 32. As in a case where each slit 32 has a circumferential length of about 5 mm, when two worked portions 33 are separated from both ends of each slit 32 by a predetermined distance, the two worked portions 33 are located in a central portion of the slit 32. In this case, it is preferable to form the worked portions 33 at both ends of the slit 32.

In the example of this embodiment shown in FIGS. 1 to 3 , the worked portions 33 are recesses connected to both ends of each slit 32, dented radially inward from the outer periphery of the skirt 22, and extending upward from an outer edge of the slit 32 in an axial direction of the cap 1 (skirt 22). Furthermore, in the example of this embodiment, the worked portions 33 have a length in the axial direction of the cap body 11 (axial length) longer than a circumferential length.

The female thread 34 is to be screwed with the male thread of the can container 100. The female thread 34 is formed in an integrated manner with the can container 100. In other words, the female thread 34 is not formed in the cap 1 as a finished product before being attached to the can container 100 and formed when being combined with the can container 100.

The tamper evident band 35 engages with the jaw of the can container 100 in a direction in which the cap 1 is separated from the can container 100, or in the axial direction of the cap 1. Furthermore, the tamper evident band 35 includes a breaking portion 35 a which is to be broken and detached from the skirt 22 when the cap 1 is opened. In other words, the tamper evident band 35 is obtained by forming a slit in the end portion of the skirt 22 while retaining the breaking portion 35 a, and the tamper evident band 35 engages with the jaw by conforming to the shape of the jaw of the can container 100 when being combined with the can container 100 as similar to the female thread 34.

The sealing member 12 is formed in an integrated manner with or separately from the cap body 11. In this embodiment, the sealing member 12 is formed in an integrated manner with the cap body 11 as illustrated in FIG. 4 .

The sealing member 12 is disposed in an inner surface the top plate 21 and is configured to seal the container mouth. The sealing member 12 is disposed in a part opposing at least the mouth of the can container 100 when capping the can container 100 with the top plate 21 of the cap 1. The sealing member 12 is formed into, for example, an annular or disk shape. Furthermore, the sealing member 12 is formed into a tubular shape protruding downward and may include a rib that abuts on the inner periphery of the mouth and an annular recess for ensuring an area that comes into close contact with the mouth.

Note that the sealing member 12 may be formed, for example, separately from the cap body 11 and may have a disk shape provided with a sliding layer on a side closer to the cap body 11 and a sealing layer on a side closer to the mouth.

Hereinafter described is a method for manufacturing the cap 1 having such a configuration.

First, a sheet-shaped metal material is drawn with a shell press apparatus to form a cup-shaped molded product. Next, the molded product is provided with the plurality of knurled portions 31, the plurality of slits 32, the plurality of worked portions 33, and the tamper evident band 35 by a molded product processing apparatus.

Next, using a sealing member forming device, the sealing member 12 is formed in the molded product provided with the plurality of knurled portions 31, the plurality of slits 32, and the tamper evident band 35. Through these processes, the cap 1 is manufactured. In this embodiment, the sealing member is formed by injection molding of a resin material.

For example, the manufactured cap 1 is collected in a collection section. When a certain number of caps 1 are collected, the caps 1 are transferred to the next process, that is, inspection and packing, where a quality inspection is conducted and the caps 1 are packed.

Hereinafter described is a method for capping the mouth of the can container 100 with the manufactured cap 1. For example, the cap 1 is mounted on the mouth of the can container 100 in such a manner that the curled portion, or a tip portion of the mouth of the can container 100, comes into contact with the sealing member 12. In this state, a load is applied to the top plate 21 of the cap body 11 and the corner 23 is drawn downward, that is, toward the can container 100, and simultaneously, the skirt 22 is subjected to the roll-on process. Accordingly, as illustrated in FIG. 1 , the corner 23 is drawn to have a predetermined shape and the skirt 22 of the cap 1 is provided with the female thread 34, whereby the cap 1 is twisted around the mouth of the can container 100 tightly. Note that such capping is performed after the can container 100 is filled with a drink. Depending on the contents, for example, the can container 100 capped with the cap 1 is subjected to retort treatment.

The cap 1 having such a configuration has the worked portions 33 at least in a part of each slit 32 in the circumferential direction on at least the side of the slit 32 closer to the top plate 21. For this reason, it is possible to prevent an upper part of each slit 32 from deforming even when a wall of the upper part of the slit 32 is decreased in diameter due to the drawing of the corner 23 of the cap body 11 when the can container 100 is capped with the cap 1.

Furthermore, providing the cap 1 with two worked portions 33 at both ends or both end portions of each slit 32 makes it possible to prevent a member contracted outside the slit 32 in the circumferential direction due to the drawing from moving into a space between the two worked portions 33 formed in the slit 32. Accordingly, it is possible to prevent deformation in the upper part of each slit 32 in the cap 1. In addition, in the cap 1, forming the worked portions 33 into recesses or protrusions reinforces the worked portions 33 of each slit 32 and makes them difficult to deform, which reduces sagging in a circumferential edge wall of both ends of each slit 32 and brings tension between the two worked portions 33.

In addition, forming the worked portions 33 into recesses or protrusions and forming the worked portions 33 to have an axial length of the cap 1 longer than a circumferential length of the cap 1 make it possible prevent the metal material outside each slit 32 in the circumferential direction from flowing into the upper part of the slit 32 during the drawing, thereby preventing deformation of the upper part of the slit 32.

It should be noted that the present invention is not limited to the above embodiment. For example, in the above example, the number of the plurality of knurled portions 31 and the number of the plurality of slits 32 are mentioned, but the number of the knurled portions 31 and that of the slits 32 can be set appropriately.

As a specific example in which at least a part of each slit 32 in the circumferential direction on at least the side of the slit 32 closer to the top plate 21 is provided with two worked portions 33, the worked portions 33 in the above example are illustrated as members formed in both ends of each slit 32 on the side closer to the top plate 21, but the invention is not limited to such a configuration. For example, three worked portions 33 may be disposed at both ends and the center of each slit 32, or one worked portion 33 may be disposed at the center of each slit 32. Alternatively, each slit 32 may be provided with four or more worked portions 33. In addition, the worked portions 33 may be disposed on the side of the skirt 22 closer to the mouth as well as the side of each slit 32 closer to the top plate 21. However, it is preferable that two worked portions 33 are disposed at both ends or both end portions of each slit 32.

Furthermore, the worked portions 33 having an axial length longer than a circumferential length have, for example, a linear shape but may have a rectangular or elliptical shape. In addition, the circumferential length and the axial length of the worked portions 33 may be the same as long as the worked portions 33 have a shape that prevent deformation.

In the above example, the worked portions 33 are illustrated as recesses or protrusions but the worked portions 33 may be, for example, slits. However, the worked portions 33 are preferably recesses or protrusions because making the worked portions 33 into slits may cause metal powder and reduces effects of reinforcement around the worked portions 33.

Note that the invention is not limited to the above embodiments, and in the implementation stage, various modifications can be made without departing from the gist of the invention. Furthermore, the embodiments may be combined appropriately, which brings about combined effects. In addition, the above embodiments include various inventions, and various inventions can be extracted by a combination selected from a plurality of disclosed components. For example, even when some components are deleted from all the components shown in the embodiments, a configuration from which the components are deleted can be extracted as the invention as long as the problem is solved and the effect is obtained.

REFERENCE SIGNS LIST

-   -   1 CAP     -   11 CAP BODY     -   12 SEALING MEMBER     -   21 TOP PLATE     -   22 SKIRT     -   23 CORNER     -   31 KNURLED PORTION     -   32 SLIT     -   33 WORKED PORTION     -   34 FEMALE THREAD     -   35 TAMPER EVIDENT BAND     -   35 a BREAKING PORTION     -   100 CAN CONTAINER (CONTAINER) 

What is claimed is:
 1. A cap comprising: a cap body including a top plate and a skirt having a tubular shape disposed on a circumferential edge of the top plate; a sealing member disposed on an inner surface of the top plate and configured to seal a container mouth; a slit extending in a circumferential direction of the skirt; and a worked portion formed at least in a part of the slit in the circumferential direction on at least a side of the slit closer to the top plate.
 2. The cap according to claim 1, wherein the worked portion is disposed in two parts, both ends or both end portions, of the slit.
 3. The cap according to claim 1, wherein the worked portion is disposed only on the side of the slit closer to the top plate.
 4. The cap according to claim 2, wherein the worked portion is disposed only on the side of the slit closer to the top plate.
 5. The cap according to claim 1, wherein the worked portion is a recess or a protrusion disposed in the skirt.
 6. The cap according to claim 2, wherein the worked portion is a recess or a protrusion disposed in the skirt.
 7. The cap according to claim 3, wherein the worked portion is a recess or a protrusion disposed in the skirt.
 8. The cap according to claim 1, wherein the worked portion has a length in an axial direction of the cap longer than a length in the circumferential direction.
 9. The cap according to claim 2, wherein the worked portion has a length in an axial direction of the cap longer than a length in the circumferential direction.
 10. The cap according to claim 3, wherein the worked portion has a length in an axial direction of the cap longer than a length in the circumferential direction.
 11. The cap according to claim 4, wherein the worked portion has a length in an axial direction of the cap longer than a length in the circumferential direction.
 12. The cap according to claim 5, wherein the worked portion has a length in an axial direction of the cap longer than a length in the circumferential direction.
 13. The cap according to claim 6, wherein the worked portion has a length in an axial direction of the cap longer than a length in the circumferential direction.
 14. The cap according to claim 7, wherein the worked portion has a length in an axial direction of the cap longer than a length in the circumferential direction. 